Because the inside is transparent and the amount of ink can be seen, it is convenient to understand the replacement timing. Even if it gets hurried suddenly, knocking can prolong life proceeding so we can surpass the meeting place etc.

Mitsubishi's whiteboard marker was hard to erase and it was hard for me to erase it so we used all the colors we've been using since before. Even if I write it on a cheap white board, it is easy to erase the written ink because it is dried in film form. Even if it gets scratched, it can be used until the end as the density revives.